Calipers.



y No. 753,233.'A PATENTED APR., 26, 1904.

P.V SHAFBR. v

GALIPBRS.

APPLIoA'rmN Hun JUNI: s. 1905.

No nonni.;

we onms'vefrns ou, mrouma, mmm-rom n c Patented April 26, 1904. 'I

FRANK SHAFER, OF OAMILLUS, NEW YORK.

QALlPERs.

SPECIFICATION forming part of Letters Patent No. 758,283, dated April 26, 1904.

Application liled June 8, 1903. Serial No. 160,572. (No model.)

TQ a/Z whom, t may aon/cern:

. Be it known that I, FRANK SHAFER, of Camillus, in the county of Onondaga, in the State of New York, have invented new and useful Improvements in Calipers, of which the following, taken in connection with the accompanying drawings, is a` full, clear, and exactl description. Y

Thisinvention relates to improvements inV desired graduation, or, in other words, to'

provide for the measurement of two substantially identical dlmenslons, one belng inside, as in the case of a bore or opening, and the other for external measurement, as in the case of a shaft or bar which is adapted to closelyT iit in said opening. ,Y Y Further objects will appear in the subsequent description. v l In the drawings, Figurel is a side elevation of my improved calipery in position for measuring the diameter of a shaft. Fig. Zis a similar elevation, partly in section, showing the device as used for measuring ,the interior diameter of a bore ork opening. Figs. 3, 4,

and 5 are 'sectional views taken, respectively,-

on lines 3 3, V4 a, and 5 5, Fig. 1. 'Similar reference characters indicate corresponding parts in all the views.-

In order to fully explain the objects of this invention, I have shown a flat straight bar 1 as provided with a tubular head 2 and graduations 3, the tubular head 2 being disposed at right angles to the bar and formed with a threaded aperture 4 in one of its side walls for receiving a set-screw 5. .Iournaled in this tubular head is a cylindrical shank,l having a depending jaw or arm 7, which is reversible and is form'ed with an engaging face 8 parallel with the axis of rotation, said shank being provided with lower and upper heads las, for instance, openings.

9 and 10, which engage the end facesof the tubular head 2 andv prevent endwise `movement of the shank 6 and its arm 7, the head 10 having a threaded portion.l 105, which-is screwed into a threaded socket 6 in the upper end of the shank 6 to enable ,the latter to be inverted into or removed tfromthe head 2.

It is evident from the foregoing description A that the arm 7 is rotatableinthehead 2- -that is, it may be reversed, so as to present the face 8 ,inwardly or outwardly, as may be desired, the shank 6 being providedwith diametrically opposite recesses 11 to receive thev inner end of the Ascrew 5, which 'operates to :hold the arm7 in its adjustedpositionor from further` rotary movement. v'

l Mounted upon the blade or bar 1 is asliding. .block lQ, having a depending arm 13, which is provided with opposite contact-faces 14 and 15, one of these faces, as 14, being used for measuring eXter' or dimensions and the other, as 15, being employed in connection with the member 7 for measuring interior dimensions, Thecontact-.face

8 of the revolving arm 7 is disposed .at one v sideof the axis ofrotation (designated. bythe reference-letter a', Figs. 1 and 2') a'distance s equal to; substantially one-half of'fthe distance lbetween the contact-faces 14 and 15, so'that thervariationin theposition of A:the contactface 8. in yits twoextreme positions at opposite vsides of` the yaxis is substantiallyequal tothe Vwidth',otthe arm 13 between'the faces, 14 and.

15. .It follows, vtherefore, that when the arm 7 is adjusted so that its contact-face 8 is presented towardthe contact-face .14 of the arm y13, as seenin 'Fig.f1, for measuringexter'nal dimensions, .the distance between saidcontact-faces 8 .and 14 v.is substantially .thesame as the distance hetweenthe contactsfaces 8 and 15 when the arm 7 is rotated in the re-V verse direction topresent theface 8 outwardly,

as seen in Fig. 2, for measuring the inside` It is now seen when the head 12 is set at the desired graduation for measuring the external Asurface of a body, as

dimensions of openings.

for instance, the shaft a, (shown by dotted lines in Fig. 1,) this head is clamped in position by a set-screw 16, operating upon a suitable gib 17, which bears vupon the blade 3, and

when it is desired to form an openingas, for instance, abore b, Fig. 2-it is simply necessaryto release the set-screw 5 and to then rotate the arm 7 a half-revolution, so that the contact edge 8 faces outwardly instead of inwardly, as seen in Fig. 1, in which instance the faces 8 and 15 are used in gaging this opening, and when it is desired to reproduce a shaft of the same dimensions it is simply necessary to return the arm 7 to the position seen in Fig. l and to again clamp it in place by the screw 5, and theoperation may be repeated for external dimensions as many times as may be desired without changing the position of the sliding block 12.

The operationof my invention will now be readily understood upon reference to the foretact-face of the first-named goingdescription and the accompanyingdrawings, and it'will be noted that the amount of' offset of the contact edge 8 at one side of the axisof revolution-of the arm? depends upon the width of the arm 13 or rather the distance between the contact-faces 14 and l5, the only requirements beingthat the amount of offset from the axis being substantially equal' to onehalf of the distance between said contact-faces lll-and 15.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, :is-

1. In a caliper, the combination with a graduated bar, an arm rotatingly mounted on the bar with its axis at right angles to the bar'and provided with a contact-face at lone vside'of its axis, and a second arm slidingly mounted on the bar and provided with opposite contactfaces separated from each other a distance equal to ,twice the distance between the conarm and its'axis of rotation.

,2. A caliper comprising a bar having a tubular head, an arm on the bar having opposite contact-faces, a second arm reversibly mounted in the head and having a contact-face located at one side of its axis of rotation a distance equal to one-half of the distance between the contact-faces of the first-named arm for the purpose described` p 3,.' A` caliper comprising a bar having a tubular head, a sliding block mounted on the bar and provided with an arm having opposite contact edges or faces, a second arm reversible in the tubular head and having a contact face or edge at one side of its axis of revolution and means for clamping the latter arm iny position.

4. In a caliper, a support, a sliding block on the support having an arm provided with opposite contact edges, means for clamping the block to the support for holding the arm in position, a. reversible arm mounted upon a rock-arm journaled in the tubular head and provided with a contact-face at one side of its axis, means for holding the arm in its adjusted position, a second arm mounted upon the bar and adjustable lengthwise thereof and provided with opposite contactfaces separated from each other a distance equal to substantially twice the distance of offset of the contact edge ofthe former arm from its axis of rotation and means for clamping the second arm in its adjusted position.

6. In a caliper, a bar having a tubular head, a sliding block mounted on the bar and provided with an arm having opposite contactfaces, a second arm journaled in the tubular head and provided with a contact-face disposed at one' side of its axis of revolution a distance equal to substantially one-half of the distance between the opposite contact-faces of the rst-named arm and means for clamping the second arm in position.

7 Alcaliper comprising a bar, two arms mounted on the bar, one arm having opposite parallel contact edges, and the other arm having a single contact-face, the latter arm being reversible on an axis parallel with said contact edges to present 'its contact-face toward or from the other arm.-

8. A caliper having a slidable jaw and a rotatable jaw, both vbars having contact-faces parallel with the axis of rotation ofthe rotatable jaw, whereby the same contact-face of the rotatable jaw may be presented toward or from the other jaw.

9. A caliper comprising a support and two measuring-jaws one being rotatable and the other slidable on the support, the sliding jaw having two contact-faces and the rotatable jaw having its axes of rotation parallel with said contact-faces and provided with a contactface at one side of said axis a distance equal to half of the distance between the contactfaces of the slidable jaw, whereby when the rotatable jaw is reversed its contact-face occupies different positions, the distance between .which is equal to the distance between the faces of the slidable jaw.

- In witness whereof I have hereunto set hand this 3d day of June, 1903.

FRANK SHAFER.

Witnesses:

AUSTIN E. DANIELs, Jr., F. W. SLooUM.

IOO

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